A low-foam, viscosity-reducing dispersant composition and its preparation method and application

Abstract

The present invention belongs to the technical field of color paste dispersion, and discloses a low-foam, viscosity-reducing dispersant composition, a preparation method and an application thereof. The dispersant composition of the present invention comprises the following raw materials in mass fraction: 50-85% of polyether-modified styrene maleic anhydride block copolymer and 15-50% of carboxyl-containing polysiloxane compound. The dispersant composition of the present invention can greatly reduce the viscosity of the aqueous pigment yellow slurry, so that the color paste has good fluidity and viscosity stability during storage, shortens the grinding time, and improves production efficiency; at the same time, the aqueous pigment yellow slurry after adding the above dispersant composition has lower foaming during grinding, reduces energy loss during grinding, improves the volume utilization rate of the container during filling, and is more convenient to operate.

Description

[0001] This application is a divisional application. The application number of the parent application is 202310904707.4, the application date is July 24, 2023, and the name of the invention is "A low-foam, viscosity-reducing dispersant composition, its preparation method and application". Technical Field

[0002] The invention relates to the technical field of color paste dispersion, and in particular to a low-foam, viscosity-reducing dispersant composition, a preparation method and application thereof. Background Art

[0003] Organic pigment yellow is a kind of water-based color paste that is difficult to prepare. Especially when preparing water-based yellow paste with a high solid content, the viscosity is often high, or even directly solidified; or the color paste with good fluidity just prepared will have problems of increased viscosity and poor fluidity after being stored for a period of time, which affects the actual use. In addition, the large amount of foam that appears during the production and grinding of the color paste is also a problem that cannot be ignored.

[0004] Therefore, how to provide a dispersant composition with low foaming and reduced color paste viscosity is a technical problem that urgently needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a low-foam, viscosity-reducing dispersant composition and a preparation method and application thereof, so as to solve the problems of high viscosity and high grinding foam of the existing organic pigment yellow slurry.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a low-foam, viscosity-reducing dispersant composition, comprising the following raw materials in mass fractions:

[0008] Polyether modified styrene maleic anhydride block copolymer 50-85%,

[0009] 15-50% carboxyl-containing polysiloxane compound,

[0010] Wherein, the carboxyl-containing polysiloxane compound has a structure shown in Formula I:

[0011]

[0012] In formula I, m=20-50, n=5-20;

[0013] The structure of A is -(CH2) x -, x=2~6.

[0014] Furthermore, in the low-foam, viscosity-reducing dispersant composition, the preparation method of the polyether-modified styrene maleic anhydride block copolymer is: styrene maleic anhydride resin, monohydroxy-terminated polyether, solid superacid catalyst and co-catalyst are mixed, and an esterification reaction is carried out to obtain the polyether-modified styrene maleic anhydride block copolymer.

[0015] Furthermore, in the low-foam, viscosity-reducing dispersant composition, the molecular weight of the styrene maleic anhydride resin is 3000-5000, the molar ratio of styrene to maleic anhydride in the styrene maleic anhydride resin is 2-4:1, the molecular weight of the monohydroxy-terminated polyether is 800-1500, and the mass ratio of the styrene maleic anhydride resin to the monohydroxy-terminated polyether is 1:1-1:5.

[0016] Furthermore, in the low-foam, viscosity-reducing dispersant composition, the solid superacid catalyst is sulfuric acid / zirconium dioxide (SO4 2- / ZrO2) and phosphoric acid / zirconium dioxide (PO4 3- / ZrO2), the mass of the solid superacid catalyst is 0.2-1.0% of the total mass of the styrene maleic anhydride resin and the monohydroxyl-terminated polyether, the co-catalyst is an alumina molecular sieve, the specification of the alumina molecular sieve is one or more of 3A, 4A, and 5A, the mass of the co-catalyst is 0.5-5% of the total mass of the styrene maleic anhydride resin and the monohydroxyl-terminated polyether, the temperature of the esterification reaction is 150-180° C., and the time of the esterification reaction is 8-16 hours.

[0017] Furthermore, in the low-foam, viscosity-reducing dispersant composition, the carboxyl-containing polysiloxane compound is prepared by mixing low-hydrogen silicone oil, alkylene acid and a catalyst, and performing an addition reaction to obtain the carboxyl-containing polysiloxane compound.

[0018] Furthermore, in the low-foam, viscosity-reducing dispersant composition, the low-hydrogen silicone oil has a structure shown in Formula II:

[0019]

[0020] In formula II, m=20-50, n=5-20;

[0021] The alkylene olefinic acid is CH2=CH-(CH2) y -COOH, wherein y=0-4.

[0022] Furthermore, in the low-foam, viscosity-reducing dispersant composition, the mass ratio of the low-hydrogen silicone oil to the alkylene olefinic acid is 3:1 to 6:1, the mass of the catalyst is 60 to 2000 ppm of the total mass of the low-hydrogen silicone oil and the alkylene olefinic acid, the catalyst is chloroplatinic acid, and the mass concentration of the chloroplatinic acid is 0.05 to 0.60%; the time of the addition reaction is 3 to 5 hours.

[0023] The present invention also provides a method for preparing a low-foam, viscosity-reducing dispersant composition, comprising the following steps:

[0024] The polyether-modified styrene maleic anhydride block copolymer is mixed with the carboxyl-containing polysiloxane compound to obtain a low-foam, viscosity-reducing dispersant composition.

[0025] Furthermore, in the method for preparing the low-foam, viscosity-reducing dispersant composition, the carboxyl-containing polysiloxane compound is treated with a non-cyclic compound containing a tertiary amine group or a cyclic compound containing a basic nitrogen heteroatom before mixing.

[0026] The present invention also provides a low-foam, viscosity-reducing dispersant composition or the use of the low-foam, viscosity-reducing dispersant composition prepared by the preparation method of the low-foam, viscosity-reducing dispersant composition in aqueous pigment yellow slurry. When preparing the aqueous pigment yellow slurry, the addition amount of the low-foam, viscosity-reducing dispersant composition in the aqueous pigment yellow slurry is 8 to 20 wt.%.

[0027] It can be seen from the above technical solution that compared with the common dispersants on the market, the low-foam, viscosity-reducing dispersant composition of the present invention has the following advantages:

[0028] (1) The dispersant composition of the present invention has a certain degree of hydrophilicity after the styrene maleic anhydride resin is modified by the monohydroxyl-terminated polyether, and the degree of hydrophilicity-lipophilicity can be arbitrarily adjusted by changing the amount of the styrene maleic anhydride resin and the monohydroxyl-terminated polyether, so it can have excellent compatibility with common water-based resins;

[0029] (2) During the production of the color paste, the dispersant composition of the present invention reduces the surface tension of water due to the introduction of the carboxyl silicone oil, improves the wettability of the pigment surface, and enables the dispersant composition to quickly reach the surface of the pigment, thereby reducing the viscosity of the color paste during production, shortening the grinding time of the color paste, and improving production efficiency;

[0030] (3) After adding the dispersant composition of the present invention, since it contains a carboxyl-containing polysiloxane compound, the color paste produced has a very low foaming amount and can quickly defoam by itself, which means that the energy loss during the grinding process is lower, which is convenient for subsequent filling and packaging; as well as a higher container volume utilization rate during the filling process, and better operational convenience;

[0031] (4) After adding the dispersant composition of the present invention, the hydrophilic-lipophilic balance of the polyether-modified styrene maleic anhydride copolymer in the dispersant composition can be adjusted arbitrarily, and the best hydrophilic-lipophilic balance grinding environment for color paste grinding is achieved by grafting styrene maleic anhydride resins of different molecular weights with polyethers of different molecular weights, thereby reducing the interfacial tension between water and organic pigments to the greatest extent, thereby obtaining the best flow state; and the carboxyl-containing polysiloxane compound can effectively suppress the foam generated during high-speed stirring, and the carboxylate ions generated after the neutralization of the carboxyl group provide the charge required for the stability of the organic pigment particles, providing a guarantee for the stable storage of the color paste. Therefore, the color paste produced by the dispersant composition of the present invention has good fluidity and viscosity stability during storage. DETAILED DESCRIPTION

[0032] The present invention provides a low-foam, viscosity-reducing dispersant composition, comprising the following raw materials in mass fractions:

[0033] Polyether modified styrene maleic anhydride block copolymer 50-85%,

[0034] 15-50% carboxyl-containing polysiloxane compound,

[0035] Wherein, the carboxyl-containing polysiloxane compound has a structure shown in Formula I:

[0036]

[0037] In formula I, m=20-50, n=5-20;

[0038] The structure of A is -(CH2) x -, x=2~6.

[0039] In the present invention, the mass fraction of the polyether-modified styrene maleic anhydride block copolymer is preferably 57 to 83%, more preferably 68 to 81%, and even more preferably 78%.

[0040] In the present invention, the mass fraction of the carboxyl group-containing polysiloxane compound is preferably 18 to 42%, more preferably 20 to 34%, and even more preferably 22%.

[0041] In the present invention, in the formula I, m is preferably 24-47, more preferably 29-38, and even more preferably 32.

[0042] In the present invention, in the formula I, n is preferably 10-19, more preferably 15-19, and even more preferably 18.

[0043] In the present invention, in the structure of A in Formula I, x is preferably 2 to 5, more preferably 2 to 3, and even more preferably 3.

[0044] In the present invention, the structure shown in Formula I is preferably:

[0045]

[0046] In the present invention, the preparation method of the polyether-modified styrene maleic anhydride block copolymer is as follows: styrene maleic anhydride resin, monohydroxyl-terminated polyether, solid superacid catalyst and co-catalyst are mixed, and esterification reaction is performed to obtain the polyether-modified styrene maleic anhydride block copolymer.

[0047] In the present invention, the mixing process is preferably: mixing styrene maleic anhydride resin and monohydroxyl-terminated polyether and heating until the raw materials are mostly melted, and then adding solid superacid catalyst and co-catalyst. The present invention has no special limitation on the melting degree of the raw materials, which can be determined according to actual conditions.

[0048] Specifically in the embodiment of the present invention, the manufacturer of the styrene maleic anhydride resin is Cray Valley Company of the United States, and the model is SMA-2000. The present invention has no special limitation on the raw materials, which can be determined according to the molecular weight.

[0049] In the present invention, the molecular weight of the styrene maleic anhydride resin is preferably 3000-5000, more preferably 3600-4500, and even more preferably 3600.

[0050] In the present invention, the molar ratio of styrene to maleic anhydride in the styrene maleic anhydride resin is preferably 2 to 4:1, more preferably 3 to 4:1, and even more preferably 4:1.

[0051] In the present invention, the molecular weight of the monohydroxy-terminated polyether is preferably 800-1500, more preferably 1200-1500, and more preferably 1500.

[0052] Specifically in the embodiment of the present invention, the monohydroxyl-terminated polyether is selected from butanol random polyether with a molecular weight of 850 (wherein the ethylene oxide segment EO accounts for 75%), polyethylene glycol monomethyl ether (MPEG 1200) with a molecular weight of 4500, or monomethoxy-terminated block polyether with a molecular weight of 1500 (wherein the ethylene oxide segment EO accounts for 55%). The present invention has no special limitation on the raw materials, which can be determined according to the molecular weight.

[0053] Specifically in the embodiments of the present invention, butanol random polyether with a molecular weight of 850 (wherein the ethylene oxide segment EO accounts for 75%), polyethylene glycol monomethyl ether (MPEG 1200) with a molecular weight of 4500, and monomethoxy terminated block polyether with a molecular weight of 1500 are all customized from Jiangsu Haian Petrochemical Co., Ltd. The present invention has no particular limitation on the preparation method of the monohydroxy terminated polyether, which is synthesized according to methods well known in the art.

[0054] In the present invention, the mass ratio of the styrene maleic anhydride resin to the monohydroxy-terminated polyether is preferably 1:1 to 1:5, more preferably 1:2 to 1:4, and more preferably 1:2.

[0055] In the present invention, the solid superacid catalyst is preferably one or two of sulfuric acid / zirconium dioxide and phosphoric acid / zirconium dioxide, more preferably phosphoric acid / zirconium dioxide.

[0056] In the present invention, the mass of the solid superacid catalyst is preferably 0.2-1.0% of the total mass of the styrene maleic anhydride resin and the monohydroxy-terminated polyether, more preferably 0.3-0.7%, and even more preferably 0.4%.

[0057] In the present invention, the co-catalyst is preferably an alumina molecular sieve.

[0058] In the present invention, the specification of the alumina molecular sieve is preferably one or more of 3A, 4A, and 5A, more preferably one or two of 3A and 4A, and more preferably 4A.

[0059] In the present invention, the mass of the co-catalyst is preferably 0.5-5% of the total mass of the styrene maleic anhydride resin and the monohydroxyl-terminated polyether, more preferably 1-4%, and even more preferably 1%.

[0060] In the present invention, the temperature of the esterification reaction is preferably 150 to 180°C, more preferably 157 to 172°C, and even more preferably 165°C.

[0061] In the present invention, the esterification reaction time is preferably 8 to 16 hours, more preferably 10 to 15 hours, and more preferably 12 hours.

[0062] In the present invention, the preparation method of the carboxyl-containing polysiloxane compound is: low-hydrogen silicone oil, alkylene olefinic acid and a catalyst are mixed and subjected to addition reaction to obtain the carboxyl-containing polysiloxane compound.

[0063] In the present invention, the process of mixing the low-hydrogen silicone oil, alkylene olefinic acid and the catalyst is preferably: mixing the low-hydrogen silicone oil and the alkylene olefinic acid, heating the mixture to the reaction temperature, and then adding the catalyst.

[0064] In the present invention, the low hydrogen silicone oil preferably has a structure shown in Formula II:

[0065]

[0066] In formula II, m=20-50, n=5-20.

[0067] In the present invention, the hydrogen content of the low hydrogen silicone oil is preferably 0.05 to 0.5%, more preferably 0.15 to 0.3%, and more preferably 0.18%.

[0068] Specifically in the embodiments of the present invention, the low hydrogen silicone oil is purchased from Jiangxi Sanyue High Molecular Materials Co., Ltd.

[0069] In the present invention, the alkylene alkene acid is preferably CH2=CH-(CH2) y -COOH ， Here, y=0 to 4, more preferably y=0 to 2, and even more preferably y=1.

[0070] In the present invention, the most preferred structure of the alkylene alkene acid is: CH2=CHCH2COOH.

[0071] In the present invention, the alkylene olefinic acid has no branched structure, so as to avoid the branched structure affecting the addition reaction between silicon and hydrogen, thereby affecting the grafting efficiency.

[0072] In the present invention, the mass ratio of the low hydrogen silicone oil to the alkylene olefinic acid is preferably 3:1 to 6:1, more preferably 4.2:1 to 5.4:1, and more preferably 5:1.

[0073] In the present invention, the mass of the catalyst is preferably 60 to 2000 ppm of the total mass of the low-hydrogen silicone oil and the alkylene olefinic acid, more preferably 400 to 1200 ppm, and even more preferably 800 ppm.

[0074] In the present invention, the catalyst is preferably chloroplatinic acid; the mass concentration of the chloroplatinic acid is preferably 0.05-0.60%, more preferably 0.15-0.40%, and more preferably 0.25%. The solvent used for the chloroplatinic acid is preferably isopropanol.

[0075] In the present invention, the temperature when adding the catalyst is preferably 120 to 150°C, more preferably 128 to 140°C, and even more preferably 135°C.

[0076] In the present invention, the time of the addition reaction is preferably 3 to 5 hours, more preferably 3.7 to 4.3 hours, and more preferably 4 hours.

[0077] In the present invention, after the addition reaction, the further step is preferably to: evacuate the obtained reaction system to remove unreacted substances and low-boiling impurities. The present invention has no particular limitation on the evacuation, and the evacuation can be carried out according to a process well known in the art.

[0078] The present invention also provides a method for preparing a low-foam, viscosity-reducing dispersant composition, comprising the following steps:

[0079] The polyether-modified styrene maleic anhydride block copolymer is mixed with the carboxyl-containing polysiloxane compound to obtain a low-foam, viscosity-reducing dispersant composition.

[0080] In the present invention, the polyether-modified styrene maleic anhydride block copolymer and the carboxyl-containing polysiloxane compound are heated when mixed; the heating temperature is preferably 50 to 90° C., more preferably 60 to 80° C., and more preferably 70° C.; the heating time is preferably 1 to 5 hours, more preferably 2 to 4 hours, and more preferably 2.5 hours. When the air temperature drops, the raw materials may freeze, crystallize, or have a relatively high viscosity. Increasing the mixing temperature of the raw materials is more conducive to uniform mixing.

[0081] In the present invention, the carboxyl-containing polysiloxane compound is treated with a non-cyclic compound containing a tertiary amine group or a cyclic compound containing a basic nitrogen heteroatom before mixing. The present invention has no particular limitation on the selection of the above compounds, which can be determined according to materials well known in the art.

[0082] The present invention also provides a low-foam, viscosity-reducing dispersant composition or the use of the low-foam, viscosity-reducing dispersant composition obtained by the preparation method in an aqueous pigment yellow slurry. When preparing the aqueous pigment yellow slurry, the addition amount of the low-foam, viscosity-reducing dispersant composition in the aqueous pigment yellow slurry is preferably 8 to 20 wt.%, more preferably 8 to 15 wt.%, and more preferably 10 wt.%.

[0083] The present invention has no particular limitation on the application method, and the application can be carried out according to methods well known in the art.

[0084] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0085] Example 1

[0086] This embodiment provides a method for preparing a low-foam, viscosity-reducing dispersant composition, comprising the following steps:

[0087] (1) Preparation of polyether-modified styrene maleic anhydride block copolymer: 150 kg of styrene maleic anhydride resin with a weight average molecular weight of 3600 (the molar ratio of styrene to maleic anhydride units is 2.5:1) and 200 kg of butanol random polyether with a molecular weight of 850 (of which the ethylene oxide segment EO accounts for 75%) were added into a 500 L reactor, and the temperature was raised to 165° C. When most of the materials in the reactor were melted, 1.4 kg of sulfuric acid / zirconium dioxide solid superacid (reagent grade, manufactured by Sinopharm Chemical Reagent Co., Ltd.) and 3.8 kg of 4A alumina molecular sieve (reagent grade, manufactured by Sinopharm Chemical Reagent Co., Ltd.) were added, and the reaction was kept warm for 10.5 h to obtain a polyether-modified styrene maleic anhydride block copolymer;

[0088] (2) Preparation of carboxyl-containing polysiloxane compound: 200 kg of low-hydrogen silicone oil with a molecular weight of 2500 and 46 kg of acrylic acid were added to a 300 L reactor, and the temperature was raised to 120° C. Then, 0.048 kg of isopropanol solution of chloroplatinic acid with a mass concentration of 0.25% was added (the amount of isopropanol solution of chloroplatinic acid was ). After the reaction was kept warm for 3.5 hours, unreacted raw materials and low-boiling impurities were removed by vacuum to obtain a carboxyl-containing polysiloxane compound, the structure of which is shown in Formula I:

[0089]

[0090] (3) First, the carboxyl-containing polysiloxane compound is neutralized with dimethylaminoethyl methacrylate to obtain a water-dispersible substance. Then, 200 kg of polyether-modified styrene maleic anhydride block copolymer and 60 kg of the treated carboxyl-containing polysiloxane compound are added to a 500 kg stirring kettle, and the mixture is heated and mixed at 60° C. for 2 h to obtain a low-foaming, viscosity-reducing dispersant composition.

[0091] Example 2

[0092] This embodiment provides a method for preparing a low-foam, viscosity-reducing dispersant composition, comprising the following steps:

[0093] (1) Preparation of polyether-modified styrene maleic anhydride block copolymer: 120 kg of styrene maleic anhydride resin with a weight average molecular weight of 4500 (the molar ratio of styrene to maleic anhydride units is 3:1) and 260 kg of polyethylene glycol monomethyl ether (MPEG 1200) with a molecular weight of 1200 were placed in a 500 L reactor, and the temperature was raised to 170° C. When most of the materials in the reactor were melted, 2.15 kg of phosphoric acid / zirconium dioxide solid superacid (reagent grade, manufactured by Sinopharm Chemical Reagent Co., Ltd.) and 4.1 kg of 4A alumina molecular sieve (reagent grade, manufactured by Sinopharm Chemical Reagent Co., Ltd.) were added, and the reaction was kept warm for 12 hours to obtain a polyether-modified styrene maleic anhydride block copolymer;

[0094] (2) Preparation of carboxyl-containing polysiloxane compound: 200 kg of low-hydrogen silicone oil with a molecular weight of 3600 and 60 kg of crotonic acid were added to a 300 L reactor, and the temperature was raised to 120° C. Then, 0.054 kg of isopropanol solution of chloroplatinic acid with a mass concentration of 0.25% was added. After the reaction was kept warm for 3.5 hours, unreacted raw materials and low-boiling impurities were removed by vacuum to obtain a carboxyl-containing polysiloxane compound, the structure of which is shown in Formula I:

[0095]

[0096] (3) First, the carboxyl-containing polysiloxane compound is neutralized with 2-aminoethylpiperazine to obtain a water-dispersible substance. Then, 184 kg of polyether-modified styrene maleic anhydride block copolymer and 76 kg of the treated carboxyl-containing polysiloxane compound are added to a 500 kg stirring kettle, and the mixture is heated and mixed at 65° C. for 2 h to obtain a low-foaming, viscosity-reducing dispersant composition.

[0097] Example 3

[0098] This embodiment provides a method for preparing a low-foam, viscosity-reducing dispersant composition, comprising the following steps:

[0099] (1) Preparation of polyether-modified styrene maleic anhydride block copolymer: 167 kg of styrene maleic anhydride resin with a weight average molecular weight of 3000 (the molar ratio of styrene to maleic anhydride units is 4:1) and 233 kg of monomethoxy-terminated block polyether with a molecular weight of 1500 (wherein the ethylene oxide segment EO accounts for 55%) were added into a 500 L reactor, and the temperature was raised to 170° C. When most of the materials in the reactor were melted, 0.45 kg of phosphoric acid / zirconium dioxide and 0.55 kg of sulfuric acid / zirconium dioxide solid superacid (reagent grade, manufactured by Sinopharm Chemical Reagent Co., Ltd.) and 3 kg of 3A and 2.5 kg of 4A alumina molecular sieves (reagent grade, manufactured by Sinopharm Chemical Reagent Co., Ltd.) were added, and the reaction was kept warm for 11.5 hours to obtain a polyether-modified styrene maleic anhydride block copolymer;

[0100] (2) Preparation of carboxyl-containing polysiloxane compound: 240 kg of low-hydrogen silicone oil with a molecular weight of 4200 and 45 kg of crotonic acid were added to a 300 L reactor, and the temperature was raised to 150° C. Then, 0.050 kg of isopropanol solution of chloroplatinic acid with a mass concentration of 0.25% was added. After the reaction was kept warm for 3.5 hours, unreacted raw materials and low-boiling impurities were removed by vacuum to obtain a carboxyl-containing polysiloxane compound, the structure of which is shown in Formula I:

[0101]

[0102] (3) First, the carboxyl-containing polysiloxane compound is neutralized with triethanolamine to obtain a water-dispersible substance. Then, 226 kg of polyether-modified styrene maleic anhydride block copolymer and 58 kg of the treated carboxyl-containing polysiloxane compound are added to a 500 kg stirred tank, and the mixture is heated and mixed at 65° C. for 2 h to obtain a low-foaming, viscosity-reducing dispersant composition.

[0103] Comparative Example 1

[0104] The competitive product 1 on the market is FX7500, and the manufacturer is Deqian (Shanghai) Chemical Co., Ltd.

[0105] Comparative Example 2

[0106] The second competitor on the market is SASOL 1900, manufactured by Sasol (China) Chemical Co., Ltd.

[0107] Comparative Example 3

[0108] The same polyether-modified styrene maleic anhydride block copolymer as in Example 2 was prepared to obtain a dispersant.

[0109] Application Examples

[0110] Preparation of water-based yellow pigment paste

[0111] Table 1. Raw material ratio of water-based pigment yellow paste

[0112]

[0113] The wetting agent is TERGITOL TM CA-90 surfactant, manufactured by The Dow Chemical Company of the United States.

[0114] The fungicide is sorbic acid and the manufacturer is Shandong Lifan Chemical Co., Ltd.

[0115] The defoaming agent is DefomW-0506, and the manufacturer is Deqian (Shanghai) Chemical Co., Ltd.

[0116] The organic pigment yellow is Clariant PV Fast HG Organic Pigment Yellow 180.

[0117] Preparation method of water-based pigment yellow slurry:

[0118] (1) Add all the raw materials described in Table 1 except organic pigment yellow into a dispersion container and stir for 15 minutes until the materials are fully mixed;

[0119] (2) Add organic pigment yellow, stir evenly, and disperse at low speed for 30 minutes;

[0120] (3) The material in step (2) was ground and dispersed for 4 h until the pigment particle size D97 reached 5 μm, and then filtered through a 200-mesh filter to obtain a water-based pigment yellow slurry.

[0121] Since the two components in the dispersant composition of the present invention are complementary, indispensable and inseparable, if one of the components is removed (i.e., the dispersant of the carboxyl-containing polysiloxane compound is removed in Comparative Example 3), the particle size D97 of the pigment yellow cannot reach 5 μm, and the manufacturing process of the color paste grinding cannot be smoothly implemented. Therefore, the experimental results of the aqueous pigment yellow paste using Comparative Example 3 cannot be tested.

[0122] During the preparation process, the grinding time and the change of the pigment particle size of the aqueous pigment yellow slurry to which the dispersant compositions of Examples 1 to 3 and the dispersants of Comparative Examples 1 to 2 were added were recorded. The results are shown in Table 2:

[0123] Table 2. Particle size changes of water-based yellow pigment slurries obtained with different dispersants

[0124]

[0125]

[0126] It can be seen from the data in Table 2 that the use of the dispersant composition of Examples 1 to 3 to prepare the aqueous pigment yellow slurry has a better grinding effect than that of Comparative Examples 1 to 2, and the grinding time can be shortened by 2 / 3.

[0127] The initial foam state and the self-defoaming time of the aqueous pigment yellow slurry prepared by using the dispersant composition of Examples 1 to 3 and the dispersant of Comparative Examples 1 to 2 were observed and recorded. After the grinding was completed, the particle size D97 of the aqueous pigment yellow slurry was tested by a laser particle size tester after standing at room temperature for 1 day, 3 days, 7 days, and 14 days, and the viscosity of the aqueous pigment yellow slurry was tested by a rotational viscometer tester. The results are shown in Table 3:

[0128] Table 3. Observation and test results of water-based yellow slurries obtained with different dispersants

[0129]

[0130]

[0131] The data in Table 2 and Table 3 show that, compared with Comparative Examples 1 to 2, Examples 1 to 3 can significantly reduce the grinding time for the production of the color paste, and the prepared aqueous pigment yellow paste has good fluidity and storage stability, and the color paste after grinding has less foaming and faster self-defoaming ability. Among them, Example 3 is the most preferred, which is substantially free of foam.

[0132] 5 parts of the aqueous pigment yellow paste prepared by using the dispersant composition of Examples 1 to 3 and the dispersant of Comparative Examples 1 to 2 were added to 100 parts of aqueous polyurethane resin, aqueous epoxy resin and aqueous acrylic resin respectively. After being evenly dispersed, proofing was performed to observe whether there was a phenomenon of roughening and producing lines, so as to judge its compatibility. The test results are shown in Table 4:

[0133] Table 4. Compatibility test results of water-based pigment yellow slurry obtained with different dispersants

[0134]

[0135]

[0136] It can be seen from Table 4 that, compared with Comparative Examples 1 to 2, the aqueous yellow pigment slurries prepared from the dispersant compositions of Examples 1 to 3 have a wide range of compatibility.

[0137] The dispersant composition of the present invention introduces a carboxyl-containing polysiloxane compound, which has a lower molecular weight and viscosity than other acrylic compounds, and diffuses faster in water after being neutralized by a non-cyclic compound containing a tertiary amine group or a cyclic compound containing a basic nitrogen heteroatom. In addition, the carboxyl-containing polysiloxane compound is helpful in suppressing the generation of foam.

[0138] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low-foam, viscosity-reducing dispersant composition, characterized in that: Contains the following raw materials by mass fraction: 200 parts of polyether modified styrene maleic anhydride block copolymer, 60 parts of carboxyl-containing polysiloxane compounds, The preparation method of the polyether-modified styrene maleic anhydride block copolymer is as follows: styrene maleic anhydride resin, ethanol random polyether, solid superacid catalyst and co-catalyst are mixed, and an esterification reaction is performed to obtain the polyether-modified styrene maleic anhydride block copolymer; The solid superacid catalyst is sulfuric acid / zirconium dioxide, the co-catalyst is alumina molecular sieve, the temperature of the esterification reaction is 165° C., and the time of the esterification reaction is 10.5 h; The carboxyl-containing polysiloxane compound has a structure shown in Formula I: The preparation method of the low-foam, viscosity-reducing dispersant composition comprises the following steps: The polyether-modified styrene maleic anhydride block copolymer is mixed with the carboxyl-containing polysiloxane compound to obtain a low-foam, viscosity-reducing dispersant composition; The carboxyl group-containing polysiloxane compound is treated with a non-cyclic compound containing a tertiary amine group or a cyclic compound containing a basic nitrogen heteroatom before mixing.

2. The low-foam, viscosity-reducing dispersant composition according to claim 1, characterized in that: The molecular weight of the styrene maleic anhydride resin is 3600, the molar ratio of styrene to maleic anhydride in the styrene maleic anhydride resin is 2.5:1, the molecular weight of the butanol random polyether is 850, and the mass ratio of the styrene maleic anhydride resin to the butanol random polyether is 1.5:

2.

3. The low foam, viscosity reducing dispersant composition according to claim 1 or 2, characterized in that: The mass of the solid superacid catalyst is 0.4% of the total mass of styrene maleic anhydride resin and butanol random polyether, the specification of the alumina molecular sieve is 4A, and the mass ratio of the co-catalyst to the total mass of styrene maleic anhydride resin and monohydroxyl terminated polyether is 3.8:

350.

4. The low foam, viscosity reducing dispersant composition according to claim 1, characterized in that: The preparation method of the carboxyl-containing polysiloxane compound comprises the following steps: mixing low-hydrogen silicone oil, acrylic acid and a catalyst, and performing an addition reaction to obtain the carboxyl-containing polysiloxane compound.

5. The low foam, viscosity reducing dispersant composition according to claim 4, characterized in that: The low hydrogen silicone oil has a structure shown in Formula II: In formula II, m=27, n=6.

6. The low foam, viscosity reducing dispersant composition according to claim 4 or 5, characterized in that: The mass ratio of the low hydrogen silicone oil to the acrylic acid is 200:46, the mass ratio of the catalyst to the low hydrogen silicone oil to the total amount of acrylic acid is 0.048:246, the catalyst is chloroplatinic acid, and the mass concentration of chloroplatinic acid is 0.25%; the time of the addition reaction is 3.5h.

7. The method for preparing the low-foam, viscosity-reducing dispersant composition according to any one of claims 1 to 6, characterized in that: The following steps are involved: The polyether-modified styrene maleic anhydride block copolymer is mixed with the carboxyl-containing polysiloxane compound to obtain a low-foam, viscosity-reducing dispersant composition; The carboxyl group-containing polysiloxane compound is treated with a non-cyclic compound containing a tertiary amine group or a cyclic compound containing a basic nitrogen heteroatom before mixing.

8. Use of the low-foam, viscosity-reducing dispersant composition according to any one of claims 1 to 6 or the low-foam, viscosity-reducing dispersant composition prepared by the preparation method according to claim 7 in aqueous pigment yellow slurry, characterized in that: When preparing the aqueous yellow pigment slurry, the low-foam, viscosity-reducing dispersant composition is added in an amount of 10 wt. % in the aqueous yellow pigment slurry.

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